Chronic Back Pain Prevalence Assessment

Chronic back pain was assessed using a self-reported questionnaire, in which participants were first asked whether they had experienced pain that had interfered with their usual activities in the last month. The following options were given to the participants: none, prefer not to answer, pain all over the body, facial pain, one or more of the musculoskeletal pain sites–neck or shoulder pain, back pain, hip pain, knee pain”. If participants provided an affirmative answer for back pain, a further question was asked about whether the participant had experienced this pain for more than three months. Those participants reporting back pain for more than 3 months were classified as having chronic back pain. Participants not reporting back pain as a pain site in the first question and/or not reporting back pain for more than 3 months were classified as not having chronic back pain. Participants who responded “prefer not to answer” or “pain all over the body” were excluded from our study.